Hi!
I'm strongly considering rolling a Mage, but more due to Fire seeming fun than anything else -- neither Arcane or Frost seem too interesting to me (particularly not the latter considering the seemingly tedious Archimonde trinket and all). Looking through WCL's Mythic statistics, Fire seems to handle itself really well on the vast majority of fights (mostly being better than the other Mage specs as well), and on those it does not, Arcane fares well.
But here's the thing: the sample size for Fire is extremtly small, which I suppose impacts the credibility of the numbers quite a bit.
So: Does Fire perform as well as it seems to be, and if so, why do so few play it?